What you need to know about Aurora's emissions test

Aurora, Illinois requires an emissions test as part of your vehicle registration renewal if your car is model year 1996 or newer. The test measures what comes out of your tailpipe—carbon monoxide, nitrogen oxides, and particulate matter—to confirm your vehicle meets state pollution standards. You cannot renew your registration without a passing test result on file with the Illinois Secretary of State.

The test itself takes about 10 minutes and costs between $25 and $35 at an authorized testing station. Aurora has multiple stations throughout the city, and you can find them through the Illinois Environmental Protection Agency (IEPA) website or by calling your local Secretary of State office. The test is straightforward: a technician plugs a diagnostic machine into your vehicle's onboard computer port and runs it through a standardized protocol.

Key Takeaways

  • Aurora requires emissions testing for vehicles model year 1996 and newer during registration renewal, and you cannot register without a passing result.
  • The test costs $25 to $35, takes about 10 minutes, and measures tailpipe emissions against Illinois state standards.
  • You can find authorized testing stations through the IEPA website or by contacting the Illinois Secretary of State's Aurora office.
  • A failing test usually means your vehicle has a problem with the emissions control system, and you will need repairs before retesting.
  • If your check engine light is on, the test station will likely refuse to test until you address the underlying problem.

Finding an authorized testing station in Aurora

The Illinois Environmental Protection Agency maintains a searchable database of all authorized emissions testing stations. You can search by zip code or city name to find stations near you in Aurora. The IEPA website lists the station address, phone number, and hours of operation for each location.

When you call ahead, confirm that the station is currently accepting vehicles for testing and ask about wait times. Some stations get busy during peak registration renewal periods, and a short call can save you a trip. You will need to bring your vehicle keys, proof of vehicle ownership (registration or title), and a valid photo ID.

What happens during the emissions test

The technician will first verify your vehicle information against your registration documents. They will then locate the diagnostic port under your steering wheel or dashboard and connect a machine that reads your vehicle's emissions data. The machine runs a test cycle that measures how much pollution your engine produces under controlled conditions.

The entire process takes about 10 minutes. Your vehicle does not need to be running during the connection—the machine reads data stored in your engine's computer. Once the test is complete, the technician will print a report showing whether you passed or failed. A passing result is transmitted electronically to the Illinois Secretary of State within 24 hours.

Why your vehicle might fail the emissions test

A failing test usually means your vehicle's emissions control system is not working properly. Common reasons include a faulty oxygen sensor, a problem with the catalytic converter, a malfunctioning fuel injector, or an issue with the engine control module. Any of these problems will cause your engine to produce more pollution than the state standard allows.

If your check engine light is on, many testing stations will refuse to test your vehicle until you have the problem diagnosed and repaired. The light indicates that your onboard diagnostic system has detected a fault, and the test station needs that fault cleared before they can accurately measure your emissions. You will need to visit a mechanic or dealership to have the problem diagnosed and fixed, then return to the testing station for a retest.

Retesting after a failure

If you fail the emissions test, you have 60 days to have your vehicle repaired and retested. The retest fee is typically the same as the initial test—$25 to $35. You do not need to return to the same testing station; you can go to any authorized station in Illinois.

Before you retest, make sure the repair shop has actually fixed the problem that caused the failure. Ask the mechanic to clear the check engine light and confirm that the specific emissions system component has been repaired or replaced. Some shops will provide a written estimate of what needs to be fixed; this can help you understand what went wrong and why the repair was necessary.

Registration renewal and emissions test timing

Your emissions test result is valid for the calendar year in which you take it. If you test in January, that result covers you through December 31 of that same year. You must have a passing test on file before you can renew your registration, but you do not have to test on the exact day you renew—you can test any time during the year and use that result for your renewal.

The Illinois Secretary of State's office receives your test result electronically, usually within 24 hours of testing. When you go to renew your registration online, by mail, or in person, the system will show your passing result. If you fail and need to retest, you have 60 days to do so; if you do not retest within that window, you will need to start the process over.

What to do if you cannot find a testing station or have other problems

If you are having trouble locating a testing station or have questions about your specific vehicle, contact the Illinois Environmental Protection Agency directly. Their phone line can answer questions about which vehicles require testing, where to find stations, and what to do if you believe your test result was incorrect.

You can also visit the Secretary of State's Aurora office in person. Staff there can help you understand your registration status, confirm whether you need an emissions test, and direct you to the nearest testing station. Bring your vehicle registration and a photo ID if you visit in person.

Frequently Asked Questions

Do I need an emissions test if my car is older than 1996?

No. Illinois only requires emissions testing for vehicles model year 1996 and newer. Older vehicles are exempt from the test requirement, though they still need to pass a safety inspection to register.

What if I just bought a used car in Aurora—do I need to test it right away?

You need a passing emissions test before you can register the vehicle in Illinois. If the previous owner did not provide you with a test result, you will need to take the car to a testing station and pass before you can complete registration with the Secretary of State.

Can I test my vehicle at any time of year, or only during my registration renewal month?

You can test any time during the calendar year. The result is valid through December 31 of that year, so you can test in January and use that result for a registration renewal in November if you need to.

What if the testing station says my vehicle cannot be tested because the check engine light is on?

The check engine light indicates a fault in your emissions control system. You will need to visit a mechanic or dealership to have the problem diagnosed and repaired, then return to the testing station for a retest once the light is off.

How long does it take to get my test result after I test?

The testing station transmits your result electronically to the Illinois Secretary of State within 24 hours. You can usually see the result in the registration system the next business day, though it may take up to 48 hours in some cases.